Field of the Invention
The inventions disclosed and taught herein relate generally to gas lift systems, apparatuses, and methods thereof. More specifically, the inventions described herein relate to increasing the production of gas wells through the use of an injection conduit fed bottle chamber of a gas well bore apparatus.
Description of the Related Art
The inventions disclosed and taught herein are directed to an improved system for increasing the production of a gas well. Although these inventions can be used in numerous applications, the inventions will be disclosed in only a few of many applications for illustrative purposes.
Gas lift systems are commonly employed to extract gas, fluids, and/or other natural resources from subterranean wells and other deposits below the Earth's surface. In gas-producing reservoirs, the gas and/or oil contained therein is compressed by the weight of the overlying earth. When the formation is breached by a well, the gas tends to flow into the well under formation pressure. Any other fluid in the formation, such as connate water trapped in the interstices of the sediments at the time the formation was deposited, also moves toward the well. Production of fluids from the well continues as long as the pressure in the well is less than the formation pressure. Eventually, production slows and/or ceases either because formation pressure equals or falls below well pressure (borehole pressure). In the latter case, it has often been found that interstitial water filling the well exerts sufficient pressure to stop or sharply reduce production. A problem arises when the expense of removing the water becomes a substantial portion of, or exceeds the value of the hydrocarbon produced, thereby making it uneconomical to operate the gas and/or oil well. At times, up to 60% of the oil and or gas reserves may remain in the formation.
Many conventional approaches for removing liquid from an oil and gas well are disclosed in the prior art. Piston pumps are common and require either an electric or gas powered motor which is coupled by belts or gears to a reciprocating pump jack. The reciprocating motion of the pump jack, in turn, reciprocates a piston within a cylinder disposed within the well. As the piston reciprocates within the well, valves open and close, creating a low pressure in the well and drawing the oil to the surface. Centrifugal or rotary pumps, often found in water wells, also operate by either an electric or gas powered motor. Usually, the pump is attached directly to the shaft of the motor. The rotary motion of the veins reduces pressure in the well, thereby causing the fluid to flow up the well.
Major disadvantage with both piston and centrifugal pumps include mechanical fatigue and failure of moving parts and high maintenance and repair costs. Furthermore, such systems require large amounts of electricity or fuel to operate, making them more costly than passive systems. Typically, the expense of maintaining and operating such systems will eventually exceed the economic benefits returned and result in the well being shut in with up to 60% of the reserves still within the formation.
In gas producing wells another major disadvantage of conventional pumps such as electrically submersible pumps, is that their efficiency can be very low unless enough hydrostatic head is provided. In gas wells it is often valuable to totally remove the standing fluid to near the bottom of the wellbore where there is simply not enough allowable fluid column height and therefore not enough hydraulic head to allow such pumps to effectively operate. Furthermore, the well accumulation rate of liquids in gas wells can be very much lower than the rate at which such pumps must run which can result in a high frequency of pump shutdown events and an increased risk of such pumps running dry and burning up.
Conventional gas lift systems often require the injection of gases, fluids, or the like—typically under highly pressurized conditions—down the wellbore in order to maximize the yield of the extracted resources. U.S. Pat. No. 4,708,595 to Maloney et al. (hereinafter, “Maloney”) illustrates one of these conventional gas lift systems.
Maloney describes an intermittent oil well gas-lift apparatus and process of lifting liquids. The apparatus includes a chamber on the downhole end of a production tubing that is in communication with a sidestring tube in communication with a high pressure gas stored with a casing above and below a packer. A valve in the sidestring permits the entrance of a lifting gas into the chamber to lift the liquid flowing therein to the surface. This increases the pressure differential between the formation and the interior of the casing and lifting chamber during the operation of the apparatus.
Furthermore, U.S. Pat. No. 6,966,366 to Rogers, Jr. (hereinafter, “Rogers”) illustrates a modified version of a conventional gas lift system. More specifically, Rogers describes a plunger enhanced chamber lift for well installations and method of retrofitting a well installation to reconfigure it to provide a plunger enhanced lift chamber lift. The wellhead is modified to supply gas under pressure into a secondary annulus and the sealing plug is removed. A check valve is provided and positioned within the coiling tube such that the secondary seal engages the secondary seating nipple. A reciprocally moveable plunger is provided and installed with the coiling tube.
Although both Maloney and Rogers' disclosures teach various implementations of gas lift systems, there are several drawback to their teachings. In particular, these solutions are only effective to varying degrees for various resources to be extracted. For example, these solutions are not effective for extracting coal bed methane, or other gases that exhibit low pressure-to-volume characteristics. Moreover, conventional gas lift systems typically require highly pressurized downhole injections that can increase the back pressure on formations. This back pressure can compromise the integrity of the formation and reduce its overall yield. Finally, conventional gas lift systems typically require large volumes of injection gas and complicated control systems to operate which, as a result, can increase the overall cost of operating the lift.
What is required, therefore, is a solution that provides a gas lift system that can increase the production yield of the formation and decrease its overall cost of operation without increasing the backpressure on the formation.
Accordingly, the inventions disclosed and taught herein are directed to systems, methods, and apparatuses for increasing the production of a gas well that overcome the problems as set forth above